(1) Field of the Invention
The present invention relates to a power window control system of an automotive vehicle.
(2) Description of the Related Art
Prior to the development of power windows, vehicle window were raised using a manual cranking device. More recently, power windows have been developed that are controlled by a power window control system.
FIG. 11 illustrates a conventional power window control system which includes a plurality of relays, a mechanical switch and a power line. Through simple switching operations using the relays and mechanical switch, the window position in each of four doors/locations can be controlled. Further, all of these windows may all be controlled from the driver's seat.
In operation, a motor M of the power window system controls opening and closing of each window. However, overloading can occur. To avoid this, the illustrated conventional power window control system separates power line 30 from the motor M using an overheat regulator to inhibit operation of motor M.
The conventional power window control system includes a mechanical switch for initiating raising and lowering of the power window. The power line 30 is directly turned on or turned off by means of the relays K11 to K13.
However, in operation, the mechanical switches and K13 for each window oxidize from arcing that occurs therein, thus generating poor switching operations and undesirable surge voltages. Since current must flow through these mechanical switches for proper operation, an expensive and strong switch is required, as well as heavy and complicated wiring. This then necessitates the use of heavy wiring between the power supply and the mechanical switch, and the mechanical switch and the motor.